Using The Setpoint Status Register; Examples Of Control Outputs - Measurement Computing PCI-2513 User Manual

PCI-2513 User's Guide

Using the setpoint status register

You can use the setpoint status register to check the current state of the 16 possible setpoints. In the register,
Setpoint 0 is the least-significant bit and Setpoint 15 is the most-significant bit. Each setpoint is assigned a
value of 0 or 1.

A value of 0 indicates that the setpoint criteria is not met—in other words, the condition is False.

A value of 1 indicates that the criteria has been met—in other words, the condition is True.
In the following example, the criteria for setpoints 0, 1, and 4 is satisfied (True), but the criteria for the other 13
setpoints has not been met.
Setpoint # 15
1 0
True ( )
0
False ( ) <<< Most significant bit
From the above table we have

Setpoint 0, having a True state, shows 1, giving us decimal 1.

Setpoint 1, having a True state, shows 1, giving us decimal 2.

Setpoint 4, having a True state, shows 1, giving us decimal 16.
For proper operation, the setpoint status register must be the last channel in the scan list.

Examples of control outputs

Detecting on analog input and FIRSTPORTC updates
Update mode: Update on True and False
Criteria: Channel 4: inside window
Channel 4 is programmed with reference to two setpoints (limit A and limit B) which define a window for that
channel.
Channel Condition
4 Within window (between
limit A and limit B) for
channel 4
Figure 18. Analog inputs with setpoints update on True and False
14 13 12 11 10
0 0 0 0 0
10011
binary, or 19 decimal, derived as follows:
State of detect
signal
True
False
9 8 7 6 5
0 0 0 0 0
Action
When Channel 4's analog input voltage is within the
window, update FIRSTPORTC with 70h.
When the above stated condition is False (channel 4
analog input voltage is outside the window), update
FIRSTPORTC with 30h.
30
Functional Details
4 3 2 1 0
1 0 0 1 1
Least significant bit >>>